Is the iphone 5s better or 5c?

I'm guessing the 5s is better because it has the A7 chip.

5S is better. The 5C is basically an iPhone 5 with plastic backs and colors.

The 5S is more advanced.

The iPhone 5S is made of high grade aluminum.
iPhone 5S has a new A7 64 bit system chip that's twice as fast as the iPhone 5 A6 chip.
iPhone 5S TouchID - use your fingerprint on the home button instead of a password.

iPhone 5C is made of hard coated polycarbonate material and steel reinforced.
It contains the same A6 processor and 8 megapixel camera as the iPhone 5.